Boiler



1929- J. J. RATHGEB, JR i 1,725,828

I v BOILER Filed p L925 2 Sheets-Sheet 1 Qwuwncoz Jose? 'J' Rn THGEB JR w J o/zwiiwafv Patented Aug. 27, 1929.

OFFICE.

JOSEPH J'. RATHGEB, JFW, OF NEW YORK, N. Y.

BOILER.

Application filed September-28, 1925.

My invention relates to coal burning furnaces for steam or hot water heating and has for its principal object the production of a novel construction of furnace in which a supplemental supply of air is admitted to the lire box to ignite the fire gases and thereby eliminate the objectionable smoke generated in most furnaces.

A further object of the invention is the pro duction of a furnace of the character de scribed having means for controlling or varying the amount of supplemental air supply to suit varying conditions.

A further object of the invention is the production of a furnace of the above character provided with two sources of supplemental air supply whereby the invention may be used either with grates of the ordinary type or with hollow air-cooled grates.

The invention also contemplates the provision in combination with a furnace of the type specified of hollow grate bars constituting the grate proper through which the sup plemental air supply passes this air supply also acting to cool the grate bars to prevent them from burning out, the air at the same time becoming heated to the degree necessary adapting it to completely and effectively ignite the fire gases.

Still further objects of the invention are the production of a furnace so constructed as to allow for the longitudinal expansion of the grate or grate bars when necessity arises and the positioning of the supplemental air supply ducts in such manner as to obviate the possibility of their burning out.

Further and other objects and advantages of the invention will be apparent from the subjoined description taken in connection with the accompanying drawings in which Fig. 1 is a side elevation (partly broken away and partly in section) of a furnace constructed in accordance with my invention.

Fig. 2 is an enlarged side elevation of the lower portion of the furnace.

Fig. 3 is a horizontal section on the line 3-3 of Fig. 1.

Fig. 1 is an end elevation of four of the grate bars or units.

Fig. 5 is a cross-section taken through one of the grate bars or units.

Referring in detail to the several figures of the drawings:

1 indicates the front brick setting of the furnace and 2 the rear brick setting thereof while 3 indicates the side walls of the setting Serial No. 58,974.

joining together the parts 1 and 2 to form the :fire boX. The front and rear walls of the furnace are indicated at 4 and 5 respectively and may support the boiler or shell 6 which is provided, as ordinarily, with a plurality of boiler tubes 7 therein receiving therethrough the heated air which flows from the fire box, into the combustion chamber 7, in the direc tion of the arrows, through said tubes 7 and out of the fine 8 to assist in heating the water in the boiler and to provide an outlet for the spent air and gases. These and other parts of the furnace and boiler or shell may be conventional and require no detailed explanation.

Although it is not to be so limited I prefer to use my invention in conjunction with an air-cooled grate and accordingly it is preferred to supply any form of power-driven blower indicated at 9 connected by the pipe 10 with the ash pit 11 beneath the grate bars to be presently describedf For the sake of illustration only I have also indicated a con ventional feed water pipe at 12 and a feed door for the fuel in the front wall at 18.

The complete grate preferably comprises a plurality of hollow grate bars 14 arranged longitudinally of and in apposition to each other and provided with serrated side edges as shown to form zigzag air slots therebetween through which the air from the ash pit flows and takes a tortuous path to insure a complete and perfect combustion of the fuel on said grate bars. The brick settings are pref-erably provided with slots 15 surrounded by heat-insulating material, said slots receiving nipples or pipes 16 which are fastened to either end of each of the grate bars and which communicate with the hollow interior thereof. This arrangement of loosely supporting the bars permits them to expand longitudinally if they become unduly heated. The front and rear brick settings 1 and 2 respectively also have embedded therein the air passageways or ducts 17 and 18 respectively which are closed at one end and which extend outwardly on one side of the furnace at their other open ends. Those walls of the air passageways or ducts which are opposed to each other are provided with longitudinal slots 18 which communicate with the slots 15 in the brick settings. The outwardly extending open ends are provided with adjustable slidable doors 19 to close said passageways or ducts when so desired to prevent the admission of air therein or they may be partially closed to vary the amount of air admitted. The rear brick setting 2 is provided with the usual upwardly extending bridge wall. 20 which preferably forms a part thereof and has a slot 21 extending upwardly therein and then outwardly to form a restricted longitudinal opening 22 all as clearly illustrated in Fig. 2. This slot 21 communicates with the air duct or passageway 18.

WVhen the furnace is in operation the blower 9 is actuated to produce a forced draft into the ash pit which flows through the zigzag air slots intermediate the grate bars and insures combustion of the fuel thereon. T he gate or door 19 at the end of the air passageway or duct 17 is opened and air will be drawn by the suction of the flue draft into said passageway, through the slot 18, through the nipples or pipes 16 adjacent that passageway, through the grate bars and into the passageway or duct 18, up through the slot 21, through the restricted opening or slot 22 and directly to the place in the tire box where the coal gases have formed so that said coal gases may be intercept-ed and ignited by the fresh supply of air before they pass through the boiler tubes 7 As the air is drawn through the grate bars it tends to cool them and prevent their over-heating but during its passage therethrough it becomes warm so that when it passes out through the restricted opening 22 it has reached the proper temperature to enable it to thoroughly perform its function of igniting the fire gases.

hen an ordinary grate is used instead of the hollow grate bars, the gate or door 19 in the air passageway or duct 17 is closed and the one in the passageway 18 is opened. The supplemental air supply then is drawn directly into the passageway 18, up through the slot 21 where it becomes partially heated, through. the restricted opening 22 Where it performs the same function as in the previous case.

Various modifications may be resorted to without departing from the spirit of my invention as set forth in the appended claim.

lVhat I claim as my invention is In a furnace of the type described, front and rear walls forming a portion of the fire box and provided with slots therein, a grate con'iprising a plurality of separated hollow units arranged longitudinally and in apposition to each other with spaces therebetween and provided with imperforate surfaces, nipples on either end of said units entering said slots, supplemental air supply duets within said walls communicating with said firstmentioned slots, an adjustable gate in each air duct for regulating the admission of air therein and a bridge wall supported. by said. rear wall and provided with an upwardly and inwardly extending slot therein extending in a direction towards said grate.

Signed at New York, in the county of New York and State of New York, this 26th day of Sept, A. D. 1925.

JOSEPH J RATHGEB, JR. 

